Human immunodeficiency virus-1 (HIV-1) is the primary cause of the acquired immune deficiency syndrome (AIDS) which is regarded as one of the world's major health problems. Although extensive research throughout the world has been conducted to produce a vaccine, such efforts thus far have not been successful.
The major goal, not previously attained, has been the generation of an immune response in a subject characterized by antibody titer generation that neutralize virus in vitro at titers reaching both the level and complexity (e.g., ability to neutralize more than one isolate) seen in human sera from infected individuals. Neutralizing antibodies in humans have mapped to the envelope protein, gp160, or one of its component parts (gp120 or gp41), and thus most vaccine efforts have concentrated on the development of envelope-protein-related antigens.
Thus, there remains a need for immunogenic substances capable of inducing an immune response in a subject (e.g., characterized by neutralizing antibodies against HIV), preferably using a single source material that induces neutralizing antibodies against a variety of field isolates of HIV. Furthermore, substances capable of inducing both systemic as well as mucosal immunity to HIV would be highly desirable, as one of the surfaces most commonly exposed to HIV in humans is vaginal mucosa.